Official GIGABYTE Forum

Downgrade Bios

Re: Downgrade Bios
« Reply #30 on: March 26, 2017, 05:38:14 am »
how do you do the hex edit on for the Nic to get original Mac address back?. Could someone who has knowledge do this for me. i can handle using fpt tool and flashing but i don't know about Hex editing is little in the danger zone for me.  i been having a time with the newest F22 bios for the Gigabyte z170 UD5. I was on F5 and it worked fine besides hiccups getting ram to run at rated speeds but now on the new bios my whole system feels sluggish. the new bios look and feels sluggish and very amateur and my ram which is rated at 3000mhz is set to 2800mhz when i set the XMP profile. If i set the values manually i can't get it to boot at all or one stick will register at 3000mhz and the other stick the system won't even recognize even though it's plugged in. i would rather have the old plain blue bios like the old days. If this bios doesn't get situated i'm selling this whole system off for something else. very shameful to be a gigabyte customer at the moment.

Also can Gigabyte provide me with a older bios i can flash like F5? I shouldn't have to hex edit to get things back to normal.
« Last Edit: March 26, 2017, 05:43:53 am by forlani101 »


  • 1214
  • 31
  • Rev 1.1, BIOS F8, Plays Xbox One S
Re: Downgrade Bios
« Reply #31 on: March 26, 2017, 03:47:09 pm »
These are the official BIOS' available for the Z170x-ud5 (including F5)

Others might be available on Tweaktown.

Are you saying your MAC, UUID, Serial Number, etc has changed since flashing to F22?  This usually happens when you replace a BIOS chip...  not when you upgrade via flash.  As mentioned by sandokan there is increased risk when using a hex editor on your BIOS. 
Z97X-UD5H\Corsair RM850w, 4790K, 16GB Vengeance, GTX970 FTW SC 4GB ACX 2.0, 850 Pro's RAID0 (boot), Black 1TB, Win10 Pro, Obsidian 450D
Nexus 6P Nougat


  • 15
  • 1
Re: Downgrade Bios
« Reply #32 on: March 26, 2017, 07:48:50 pm »
These are the official BIOS' available for the Z170x-ud5 (including F5)

Others might be available on Tweaktown.

Are you saying your MAC, UUID, Serial Number, etc has changed since flashing to F22?  This usually happens when you replace a BIOS chip...  not when you upgrade via flash.  As mentioned by sandokan there is increased risk when using a hex editor on your BIOS.

Intel NIC MAC address change when you downgrade BIOS with FPT (this is also written in the readme file). The only way to correct the MAC address it to edit the BIOS with an hex editor and flash it again (with q-flash).
Actually FPT is the only tool to downgrade from a Kabylake bios to a Skylake bios.

Re: Downgrade Bios
« Reply #33 on: March 27, 2017, 03:47:08 am »
     I think i got my UD5 system stable now with the F22 bios. Main problem was with my ram, i could not for the life get it to accept 3000mhz. i would punch in 30 for the multiplier and reboot to bios and it would keep saying 2800mhz. Something is not right with the ram portion of this board. I think i'll stick with F22 because at this point i feel like this board will break down if poked at too much. Be nice to have the option to officially downgrade the Bios to a older version. The look and layout of the F20's Bios looks terrible and i'm a person who likes to tinker and it's really cumbersome when i have to go into the Bios and mess around. Anyway......

     The ram voltage readings are off software wise. My ram is spec at 1.35v but when you type that in it will go to 1.36v and will not let you put in 1.35v. When you reboot it will say 1.368v in the Bios. When i checked with meter it said 1.344v Luckily i can check that stuff out with my digital multimeter on the boards read points. Another thing if i leave Vccio on Auto with my ram set at spec 3000mhz it will pump 1.296v which is way tooooooo high. I set it to 1.150v for stability on the ram while also being safe. The offset system for cpu is wonky as hell too. for $179 i feel scammed with the lazy bios implementation. Seriously quit with trying to copy other manufacturers uefi bios because it's terrible. I just want functionality.

Please someone relay this to the top dogs at Gigabyte to look into why this ram is such a hassle in my UD5 board and my other complaints. My ram is listed as being supported on Gigabytes product page for the UD5 board. I been using Gigabyte boards since 2007 and i've seen a steady decline in quality but that can be said about everything with big business, maximize those profits eh!?

Ram:  Vengeance┬« LPX 16GB (2x8GB) DDR4 DRAM 3000MHz C15 Memory Kit - Black (CMK16GX4M2B3000C15) 
« Last Edit: March 27, 2017, 04:08:52 am by forlani101 »


  • 1
  • 0
Re: Downgrade Bios
« Reply #34 on: April 13, 2017, 01:39:30 am »
Hi, FidoX!!

I'm having the same issue, but on a GA-Z97X-SLI motherboard also from Gigabyte.
Can you tell me where did u get the FPT for your motherboard model?
I'm trying to find it for my Z97X-SLI, but to no avail until now!
I thank you very much in advance.
If you want to, you can email me at
Hope to hear from you.
Best regards,

Re: Downgrade Bios
« Reply #35 on: April 19, 2017, 04:51:18 pm »
Hi guys, I'm having the same exact problem but with a Z270 board.. is there any new update that will work with this board? the FPT tool listed in this thread is not working with my z270 board and is saying its the wrong version.

If you want some backstory, this is the hell I've been going through:
Please help if you can.. thank you.


  • 5
  • 0
Re: Downgrade Bios
« Reply #36 on: April 20, 2017, 12:39:30 am »
Hi there !

I have installed latest Bios for my motherboard model GA-Z170-D3H version F20.
I have setup everything back like it was before update and this version makes my computer slower and unstable.
Before i had version F20b which was perfectly fine and no problems at all.
Is there anything i can do or downgrade to previous version ?

Thanks in advance,

I had the problem where updating the BIOS as suggested by the Gigabyte SIV on my z170 Gaming 7 MB basically bricked the computer. This was in conjunction with the Windows 10 Creators update, big mess... Anyway I was able to downgrade the BIOS by creating a bootable usb key with rufus (fat32). I used fpt_DOS-Z170(.zip); copy the file to the new bootable key. Copy the bios data file onto the key and rename it as bios.bin. When the key boots, it will autoexec straight into flashing the old bios. The computer rebooted a few times, but afterwards, I had the BIOS successfully downgraded to F8.

I only tried to update the BIOS because the SIV stopped working properly after the Windows 10 Creators update. But updating the BIOS caused an endless cycle of "can't locate the boot partition". This was strange, because in the command prompt (advanced recovery option) all of the drives were there with all of the data. I assume the F21 BIOS simply screwed up the partition location as far as the boot manager is concerned, Don't know, but downgrading the BIOS got me back into Windows. SIV is still broken, but it's better than not being able to boot at all. About 8 hours of work just to recover, hope it helps save someone else the time, then it isn't a total loss. You are never a total failure if you can be used as an example of what not to do. Don't upgrade your BIOS unless you have to.

Re: Downgrade Bios
« Reply #37 on: June 05, 2017, 05:19:04 pm »
Just wanted to say this was extremely helpful to me.  I have a Z170X-Ultra Gaming and made the fatal error of upgrading F4 bios to F22.  What a nightmare.  Fortunately I found this thread - very helpful.

One thing to note for my situation:  I could not boot from rufus USB when at F22 bios.  What worked was to flash F20 bios version from the Gigabyte console and then the PC booted from the USB and updated backwards to F4 which I had renamed and loaded on the stick per instructions in this thread.  Saved me countless hours of aggravation.  Thanks to all.